It's Saturday night in a New York hotel bar, and I’m running my fingers through Jordan Belfort’s hair. The real-life Wolf of Wall Street is adamant that I see for myself that he does, in fact, have the odd grey strand. “If I dyed my hair, as people accuse me of doing, then I wouldn’t have any,” he reasons. I tell him, for the third time, that I can’t find a single one. In truth, I strongly suspect his hair-ruffling request was a sneaky bid for an ego stroke.

At 51 years old, the infamous former stockbroker and convicted white-collar criminal is in unfeasibly good shape, especially considering his epic drug use, as depicted by Leonardo DiCaprio in the recent blockbuster. “I know, I should look like Keith Richards, right?” beams Belfort proudly.

Small, tanned, clad in sportswear and sunglasses, the fast-talking Belfort still has swagger but long gone is the coke-snorting, hooker-shagging, yacht-sinking hedonist of his heyday. Not only has Belfort been clean for 17 years but he’s also reinvented himself as a globetrotting motivational speaker and consultant in wealth creation.

And far from meeting in a plush Manhattan suite as one might expect, we’re in the aggressively air-conditioned lobby bar of a nondescript airport hotel; Belfort is leaving for Iceland in a couple of hours.

Later this month, he’ll be travelling to London too, to teach his Straight Line System at a one-off event at the ExCel Centre. “It’s a formula for achieving wealth and success in pretty much any business,” he explains. “The seminars attract entrepreneurs, stockbrokers, real estate brokers. But sales is not only for salesmen. I teach persuasion and communication — it’s a strategy for anyone, to create certainty in someone else.”

Dirty money: Leonardo DiCaprio as Jordan Belfort in The Wolf of Wall Street

He claims to have helped tens of thousands of ordinary folk become millionaires, legally and ethically. “Just go to my Facebook wall, my fansite,” he urges. “There are hundreds and hundreds of people leaving unsolicited messages, saying, ‘You’ve made me rich, you’ve changed my life’. Belfort may have shed the excesses of his wilder, younger years but his robust self-belief remains fully intact.

Wolf fever firmly gripped London this winter, with bankers — to many of whom Belfort remains a hero — donning Nineties power suits to watch the film. And Belfort believes he still has much to teach us. “The problem in countries lsuch as the UK is that people shy away from an entrepreneurial mindset because they’re too scared to fail.”

Failure, Belfort believes, is an essential step on the journey to success. “But there’s two types of failure: failing elegantly — when you maximise the lessons but you don’t blow out — and failing miserably. And I’m an expert in failing elegantly.”

Born in Queens, New York, raised in suburban Long Island, the self-proclaimed “money-crazy kid” set up Stratton Oakmont, a boiler-room stocktrading house, and by 26 was earning almost a million dollars a week. He filled private planes with prostitutes for office away-days, crashed helicopters and a fleet of Ferraris while out of his mind on Quaaludes, and left his first wife for a leggy model, who eventually divorced him too. By 36, however, his kingdom came crashing down — he was arrested on 22 counts of stock manipulation and money laundering, having defrauded more than 1,500 investors.

Martin Scorsese’s Hollywood adaptation of the tale of rags-to-riches to 22 months in a state penitentiary — where Belfort began writing his autobiography — has sent demand for his speaking engagements into the stratosphere; in the coming fortnight alone, he will visit Kuwait, Dubai, Oman, Vancouver, Las Vegas, Calgary, Sydney and Singapore, and he’s now landed a reality television show on a major US network. “Top salesmen in different industries from all over the world will compete to win,” he explains. “Like The Apprentice on steroids, and funny — because I’m a funny guy, you know? I’ll be the host, the Simon Cowell,” he fizzes.

I point out that some might find it offensive that he continues to profit so from his previous ill-gotten gains. He pauses, looking thrown for a second. “But I’m about to do a US tour and I’m giving 100 per cent of the profits to the government, to help pay back the investors I owe money to,” he says. He hopes to raise up to $50 million (£29.6 million) — almost half the $110 million his original sentence demanded he return.

But in a post-Occupy Wall Street world, with rising inequality, even the notion of seminars with a message so mercenary may itself seem somewhat unethical, I suggest. “Wealth creation, in the absence of greed, when it’s being done ethically, is an amazing thing,” he asserts. “It elevates society.”

DiCaprio with co-star Margot Robbie in the film

NOT SO, I say, according to Thomas Piketty’s surprise bestseller, Capital in the Twenty-First Century, which argues that increased personal wealth does not elevate society, or trickle down at all, and we are heading towards the sort of “patrimonial capitalism” that so worried Karl Marx.

“Capitalism is the system, so you might as well learn the rules and win at it,” he says with a shrug. “You can say, ‘Oh, this sucks, this system’s unfair’, but that’s a story people tell themselves that stops them from getting wealthy and succeeding.

“I love money, I’m not going to deny that,” he admits. “But I also love to give it away — I’m very generous, and I help everybody I can. I do charity work in the townships in South Africa. Shame on me that I misused money when I was young. But most people don’t get a second chance, and I did.”

He sees the seminars as part of his mission to make amends. “I could make money in other ways; I’m an expert at venture capital and this is a grind. But I once was a bad guy that used the gift I had to hurt people, and now I’m using it to help people,” he concludes.

There is certainly no shortage of people Belfort hurt, from his ex-wives to investors, to the colleagues he brought down with him by co-operating with the FBI. Does he feel guilty?

“No guilt,” he says, shaking his head firmly. “Guilt is a terrible, destructive emotion. I do feel remorse, though. And over one thing, really — that people lost money. That’s it.”

A possible jail term of 12 years was commuted to just 22 months, which Belfort believes was sufficient. “I think that I needed to go to jail for sure, but I’m not violent, I’m not a rapist,” he says. “The judge was very smart, he picked a term that wasn’t going to destroy my life but would teach me a f**king lesson, which I deserved to be taught. And they needed to put me back to work to pay the fine.”

The ever-industrious Belfort spent his prison time studying Tom Wolfe’s novel Bonfire of the Vanities, in order to craft his autobiography. “I ripped it apart until I could write like Tom Wolfe, in his voice,” he says. “I cracked his code. The same way I cracked the code for selling, I cracked Wolfe’s code for writing.”

When he was released, he told his children: “Daddy’s going to write a bestseller. My sole mission was to earn back their respect.” These days, he says, he is close to them both; his son, Carter, 18, is about to graduate from high school, and his daughter, Chandler, 20, is at college.

Belfort himself lives in Manhattan Beach, California, where he plays tennis for three hours a day, and is engaged to Anne Koppe, a divorced “soccer mom” whom he met six years ago. While his lifestyle is relatively modest compared to the gluttonous indulgences of the past, some wolfish vestiges remain. “I travel first class, and whenever I can I’ll fly in a private plane, I don’t care what it costs,” he admits blithely. “I don’t do it to be ostentatious — my schedule is such that I can’t survive without it.”

I accompany him as far as check-in, where he discovers that Iceland Air, in fact, has no first-class cabin, so he must settle for business class, but he takes the news on the chin.

As he heads for security, I ask what he’d want his legacy to be. “The guy who paid back everything,” he says without a second’s pause. “And is the greatest redemption story ever.”